No problem, we've got 1991 and 6500 to multiply
1991 × 6500 = 6500 × (1991)
+ 6500 × 1 that equals 6500
+ 6500 × 90 what gives us 585000
+ 6500 × 900 which equals 5850000
+ 6500 × 1000 that equals 6500000

= 12941500
